Cooler for air compressors



Aug. 3 1926.

F. w. PARSONS- COOLER FOR AIR COMPRESSORS Filed Oct. 14, 19

N: INVENTOR I Radar-131K214? P0700116 H5 ATTOR Patented Aug. 3, 1926.

UNITED STATES PATENT OFFICE.

FREDERICK W. PARSONS, F ELMIRA, NEW YORK, ASSIGNOR 'IO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A. CORPORATION OF NEW JERSEY.

COOLER FOR AIR COMPRESSORS.

Application filed October 14, 1925. Serial No. 62,397.

This invention relates to air coolers for multi-stage compressor units having low pressure and high pressure cylinders, and more particularly to that type commonly termed inter-coolers employed for cooling compressed fluids, such as air, in passing from the low'pressure cylinder to the high pressure cylinder.

In compressing air by ordinary commercial apparatus it is impractical to maintain isothermal conditions perfectly within the compressor cylinders. It has been found more expedient to cool the air by external means between compression stages and so to reduce the amount of energy required to be expended in compressing the air at 'the higher stages.

Another object of cooling the air before admitting it to the higher com pression cylinders is to. prevent overheating of the working parts and more especially of the lubricant which might otherwise explode and cause damage. One of the most efficient and practical coolers heretofore employed has been the multi-pass water cooled tubular type which provides efficiency and compactness of construction which are highly desirable features; At usual working speeds these coolers are effec- 80 tive but in case it is desired to increase the operating speed temporarily or permanently of a compressor designed for a relatively low speed, dangerous conditions of heating may result in the higher compression stages.-

The type of cooler above referred to has been found to be most effective for, low pressure loss and heat absorption from the air within a given range of temperatures, es-

pecially if the final air temperature is some-' 4 what higher than the water temperature. It

is an object of this invention, to combine in a unitary structure two stages of air cooling, one including an auxiliary or supplementary cooler, the object of which is to finally extract the objectionable heat from the previously cooled air preparatory to its delivery to higher compression stages. 7

Another object is to remove the entrained moisture from the air more thoroughly than has been possible in previous coolers and to provide a storage where such moisture may accumulate pending drainage by the opera tor.

Further objects will in part be obvious and partly be pointed out hereinafter.

In the accompanying drawing, forming part of the specification, is shown an elevation in sect-ion, of a multi-stage compressing unit equipped with a cover constructed in accordance with the practice of the invention.

Referring to the drawing, a lowpressure cylinder A anda high pressure cylinder B are shown mounted in parallelism on a bed plate C and secured thereto by bolts D and E respectively. A flanged discharge pipe F mounted onthe low pressure cylinder forms a support for one end of an inter-cooler G. The other end of said inter-cooler. is supported by a flanged T-connection'I-I mounted on the high pressure cylinder B. A piston J reciprocating within the cylinder A compresses the air drawn into the cylinder through inlet valves K and discharges the compressed air into the inter-cooler G through the discharge valves L and through the discharge pipe E into the inter-cooler Gr. The high pressure cylinder B is provided with a similar piston O to compress the air entering the cylinder from the inter-cooler through inlet valves P and the air thus compressed is discharged through discharge valves Q into the T-connection H.

l/Vater heads R and S are provided for the low and high pressure ends respectively of the inter-cooler and communication is provided between the heads R and S by tubes T and U.

In order to cause the air flowing through the inter-cooler from the low pressure cylinder to Contact with a greater area of the tubes T and U, a plurality of baflies V are arranged in staggered formation in the inter-cooler sothat the air in flowing through said inter-cooler is caused to follow a serpentine path. In this instance, the flow of the cooling water is counter to the flow of the air through the. inter-cooler so that the final contact of the air before passing out of the inter-cooler is with that section of the tubes wherein the temperature of the water is the lowest. The Water head S is provided with a chamber W to receive the water, and water thus admitted into thischamber flows through the group of tubes T into the water head R from whence it is returned through the group of tubes U into a chamber X in the water head S. A suitable connection Y is secured to the watt-r head S to provide an outlet for the water from said chamber.

Ordinarily in machines of this type a direct connect-ion is formed between the inter-cooler G and the high pressurecylinder B, but in accordance with the present invention, a chamber Z is formed at one end of the intercooler and communicates with a high pressure cylinder through an auxiliary cooler 12 preferably arranged vertically and connected atone end to the inter-cooler by bolts 0, and at its other end to a flanged connection (Z of the cylinder by means of boltsc.

In order to further reduce the temperature of the air flowing from the low pressure cylinder, a coil 7 is arranged within the auxiliary cooler Z). In this instance, the coil fis in communication with a source of water supply through an extension g and V the water'thus admitted into the coil is carried into the chamber XV of the water head S through a pipe h. Leakage of air along the extension g from the auxiliary cooler is prevented bya packing .j and a gland is and a similar packing and gland are also arranged aboutthe pipe it.

Means are provided to cause the air in its passage through the auxiliary cooler to flow directly over the coil f, and to this end a filler 0, which :may be cylindrical as shown or of any other suitable form, is preferably arranged concentrically inside of the coil. Legs p preferably formed integrally with the filler 0% serve as supports for the filler and are secured to the auxiliary cooler by meansof rivets g. V

.Heretofore in cooling devices employed for the purpose described, a considerable portion .of the moisture present in the air drawn into the low pressure cylinder was carried through the high pressure stage into the storage receiver. Such moisture in the storage receiver not only lowers the efficiency of the pressure fluid, .butduring its passage through the tools to be actuated washes away the lubricant and consequently causes excessive wear on the movable parts of such tools. By means of the present invention moisture carried by the air'through the coolers will be deposited in the lowermost portion of the auxiliary cooler b, from whence it may flow into a storage (not shown) formed by a hollow pedestal 7- which supports the high pressure cylinder B. A water gauge 8 secured to the auxiliary cooler 11 indicates the level of the water. Whenever the water in the lowermost portion of the auxiliary cooler '6 reaches a certain level it may be drained by means of a suitable valve t secured to the pedestal r near its base in any position convenient to the operator.

.From the forego ng description, it will be observed that the direction of flow of the water is at all times counter to the direction of the flow of the air through the coolers, so that the final contact of the air with the cooling element is at a point where the temperature of the water is the lowest.

The advantages of the "invention reside in the fact that a machine equipped with this invention which may be termed a supercooler as herein described will not only render more efficient service while operating at normal speed, but that the machine may also be operated at a higher rate of speed with good efiiciencyand without-danger of overheating. A further advantage is that a super-cooler constructed in accordance withthe present invention may be attached to .machines now :in use by means of a few slight alterations and at a nominal expense.

I claim:

1. In a device for cooling air between compression stages in multistage air-compressors, the combination of a imulti-pass intercooler having water heads at opposite ends thereof, and adapted to receive the discharge air from a low pressure cylinder, and an auxiliary cooler adapted to the connected to the said intercooler and to conduct the air therefrom to a high pressure cylider, a coiled pipe in the said auxiliary cooler connectedto a'supply of cooling water and also connected toone of the said Water heads of the said intercooler and .a filler within the said auxiliary cooler for directing the air to contact with the said coiled pipe.

2. In a device for cooling air between compression stages :in .niulti stage air compressors, the combination of a multipass intercooler havingwater heads ato-pposite ends thereof andfa'dapted to receive the discharge air from a low pressure cylinderan auxiliary cooler in the form of a tank adapted to be connected to the said intercooler :and'to conduct-theair therefromto a high pressure-cylinder, a coiled pipe carranged within the said tank connected at one end to a source of cooling water and=at the other end to one ofthe said water heads of the intercooler an-d a filler located within the coiled pipe in the said tank for direct ing the air to contact with zthe said coiled pipe. y

3. In a device for cooling .air between compression stages .in multi-stage air compressors, the combination of a multispass intercooler mounted transversely on the cylinders of a compressor and adapted to receive the discharge air from a low pressure cylinder, tubes in said intercooler-toconvey water, a water head at each end of the intercooler to supply waterto the tubes, battles in the intercooler staggered to deflect the air to all parts of said intercooler, a vertical.

auxiliary cooler adapted to be interposed between the intercooler and a high pressure cylinder and having a water tube connected with a source of water supply and coiled through said auxiliary cooler for further reducing the temperature of the air during its passage to the high pressure cylinder, said tube also being connected to convey water to one of the said water heads on the int'ercooler, a filler within the auxiliary 10 In testimony whereof I have signed this 1 specification.

FREDERICK W. PARSONS. 

